In addition to the direct complex formation between amylose and NaOH,
another possibility of a new strong complex formation of amylose caused by NaOH addition must be pointed out. After NaOH penetrates into starch granule, the lipids originally included in amylose could react with NaOH to generate the sodium salts of higher fatty acids. These sodium salts (soap) of higher fatty acids such as palmitic acid, should work as strong surfactants with large hydrophobic groups and hydrophilic groups, and could form new strong and stable complexes with amylose. The main driving force of this complex formation is a hydrophobic bond, which is further strengthened by the existence of a hydrophilic group with polarity. Some of the ionic surfactants were suggested to be able to complex even with amylopectin (Evans, 1986).